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Home   /   E&T program   /   Continuous Professional Development   /   Thermal hydraulics and safety - International school in nuclear engineering

Thermal hydraulics and safety - International school in nuclear engineering

Nuclear reactor

Pressurized water reactors (PWR)

Thermal hydraulics

Average participant satisfaction score

In summary

The ISNE international training course aims at promoting knowledge in the field of nuclear sciences. This module breaks down into two distinct parts: the "Thermal hydraulics of light water reactors (LWR)",
and "Modelling and multi-phase phenomenology of severe accidents in LWRs ".

Who should take this course ?

The doctoral course is designed for young researchers, PhD students, post-doctorates and engineers from nuclear industry companies, research centres, Universities, Technical Safety Organizations (TSO), regulatory bodies.

Learning outcomes

See the 2023 International School Brochure

  • Describe the various scales of two-phase flow modelling and their significance.
  • Present the different formulations of the 1D two-phase flow modelling (number and nature of balance equations, set of dependent variables, closure laws).
  • Give practical and relevant examples of thermal hydraulics models in the nuclear field.
  • Identify and to discuss the major physical phenomena involved during design basis accident and severe accidents.
  • Describe the different scenarios of core degradation and corium interactions during severe accidents.
  • Present the hydrogen risk in LWRs.
  • Technical visit organized (if possible, depending on the availability of the experimental facilities)
  • On-field experience, case study and tutorials
  • Lectures taught by international experts, including :

Dominique Bestion, Director of Research at CEA

He has been developing two-phase flow models for the CATHARE system code for 35 years, and has coordinated two-phase flow modelling in the NEPTUNE French multi-scale thermalhydraulics platform. He is chairman of the technical meetings of the FONESYS international network of code developers.


Florian Fichot, Expert at the Institut de Radioprotection et de Sûreté Nucléaire (IRSN)

He has been working for 25 years in the field of severe accidents. He contributed to the modelling of core degradation, thermal hydraulics and corium behaviour during the development of ICARE/CATHARE and ASTEC codes. He was coordinator of the IVMR European project (2015-2020). 


Etienne Studer, CEA International Expert in fluid mechanics and hydrogen risk issues

He has 30 years of experience working in the field of hydrogen risk in nuclear power plants, and has participated to international experimental programs, international working groups and state-of-the-art reports. He takes part to the “European Hydrogen Safety Panel”.


Full biography of our experts is available inside the School brochure (please check the "LEARNING OUTCOMES" section).
- Basic phenomena in single- and two-phase flow.
- Thermal hydraulics phenomena in LWRs.
- Multi-scale approach of LWR thermal hydraulics.
- System code modelling of reactor thermal hydraulics including advanced modelling.
- Simulation of LWR design basis accidents.
- Application of two-phase CFD to some reactor thermal hydraulics issues.
- Multiphase phenomena and modelling of severe accidents in LWRs.
- Hydrogen risk.
Minimum background: Master of Science in Nuclear Engineering.

Teaching method and tools

On-site visit



INSTN Saclay

Course organiser :


Program organiser :

+33 1 69083291

training sessions

Group limited to 24 trainees

If you are disabled, please contact the disability correspondent at the following address: instn-handicap@cea.fr

No training session is scheduled for the moment, if this training interests you, please contact us.

From 2023 january 30
To 2023 february 03
INSTN Saclay 0.00€ excl. taxes REGISTER

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